Rotary abrading device



w. w. WICKMAN ROTARY ABRADING DEVICE Filed Jan. 3, 194:7

ROTARY ABRADING DEVICE Wiley W. Wickman, Los Angeles, Calif.

Application January 3, 1947, Serial No. 720,051

8 Claims. i

This invention relates to a rotary abrading device and is particularlydirected to improvements in sanding drum construction of the typeemploying a plurality of abrasive strips extending outwardly from ahousing.

In conventional sanding drum constructions a central element is providedfor regulating the length of abrasive strips which extend outwardly incontact with resilient elements, such as brushes. Such conventional feedregulating devices are cumbersome, complicated, expensive tolmanufacture and difficult to keep in adjustment.

It is the principal object of this invention to avoid such difficulties'and to provide a rotary abrasive device having simplied and improvedmeans for clamping the abrasive strips against outward movement.

Another object of this invention is to provide a plurality `of spacerspositioned at intervals arounda central rotary member and having endmembers separated by the spacers, the end members being provided withinclined surfaces so that upon axially clamping the end members .towardeach other, the spacers are moved outwardly to clamp abrasive strips`against abutments which are provided on the end members.

Another object is to provide such spacers in the form of brush holderswhich may loe-individually turned to a selected position prior toclamping between the end members.

Various other objects and advantageous features of this invention may behad from the fol-y lowing description, and one embodiment thereof may beseen in the accompanying drawings wherein similar characters ofreference designate corresponding parts, and wherein:

Figure l is a perspective View of a preferred embodiment of myinvention, the top half of the housing being omitted for clarity ofillustration;

Figure 2 is a sectional elevation thereof, the

upper half of the housing and the clamping nut being shown spaced awayfrom the remainder of the assembly prior to installation;

Figure 3 is a fragmentary perspective view of a portion of the housingillustrated on an enlarged scale;

Figure 4 is a fragmentary perspective View illustrating the manner ofattaching the abrasive strips to the central member; Aand Figure 5 is afragmentary sectional plan View illustrating the clamping action forholding each abrasive strip between a brush holder and a cooperatingabutment.

Referring to the drawings, a housing generally designated I0 comprises apair of duplicate halves Ii and l2. Each of these halves comprises anend member on which a plurality of axially extending iingers i3 isprovided. A central opening It extends axially through each of the end.members for reception of a central sleeve member I5. Threads I6 areprovided on oppo-` site ends of the central sleeve member I5 and nuts Ilare adapted to be received on the threads i6.

The ngers I3 on the opposed members II and i2 do not meet in'end to endcontact upon assembly of the members with relation to the central sleevemember I5, but on the contrary are spaced by the axially extendingspacers or brush holders i8. These brush holders I8 may be cylindricalin shape and are preferably provided with square ends IB and 20. Theseends I9 and 2l) do not rest upon corresponding flat surfaces, but areengaged by inclined cam surfaces 2l and 22 formed on the end members I2and II, respectively.

The fingers I3 partially encircle each of the brush holders i8 andprovide an abutment surface 23 on one side, as shown in Figure 3. Aplul'25 rality of abrasive strips 24 are wound around the central sleevemember I5 .and each of these strips extends outwardly between a brushholder I8 and its corresponding abutment surface 23. A plurality ofbuttons 25 are mounted on the central sleeve member I5 and are adaptedto receive slots (not shown) in the individual abrasive strips forsecuring the strips relative to the central sleeve I5.

When the end members are assembled into operative relationship and thenuts yIl are tightened, the end members are urged to move axially in adirection toward each other and this action causes the inclined camsurfaces 2| to move each of the brush holders IB outwardly. The outwardmovement of the brush holders is arrested by the ngers I3 since thewidth of the opening W, as shown in Figure 5, is less than the diameterof the brush holders I8. Tightening of the nuts therefore serves toclamp the abrasive strips 24 between one of the brush holders I8 and thecorresponding abutment surface 23 on the ngers I3.

Each of the brush holders I8 is provided with tufts of brushes 26 whicharepreferably arranged in a straight line and which extend outwardlythrough the opening W between adjacent fingers' I3. Since the brushholders are not rigidly attached to either oi the end members II and I2,upon relaxing one of the nuts Il the brush holders can be turned abouttheir respective longitudinal axis to orient the brushes in any desiredposition within the limits dened by the opening W. The active side 2 ofthe abrasive strips contacts the abutment surface 23 and the i'elativelysmooth, inactive side lies adjacent the brushes 2G.

In operation, the abrasive strips are extended to the desired extentadjacent each of the brush assemblies and the nuts Il are thentightened, thereby forcing the brush holders i3 radially outwardly toclamp the abrasive strips in the selected position. If desired, theabrasive strips may then be trimmed by means of shears for uniformextension. The entire device is then mounted as a unit for rotation. Thecentral opening 28 in the sleeve member I is adapted to receive' adriving shaft (not shown) and the pin 29 may be used to connect theshaft and sleeve in driving relation. The device is rotated in thedirection shown by the arrow in Figure l. The clamping arrangementprovided insures that the abrasive stripsv remain in the selectedposition until the nuts il are laxed to permit the abrasive strips to bedrawn outwardly to present a new surface.

Having fully described myinvention, it is to be understood that I do notwish to be limited to the details herein set forth, but my invention isof the full scope of the appended claims.

I claim:

1. In a rotary abrading device, the combination-of: spaced end membersconnected by a central axial member` a plurality of spacers positionedat intervals around the central member and extending between `the endmembers, abutments provided on at least one of the end members extendingadjacent said spacers, a plurality of abrasive strips encircling thecentral member and each having an end thereof extending outwardlybetween one of the spacers and the adjacent abutment, and means on theend members for moving the spacers radially outwardly to clamp theabrasive strips between the spacers and the abutments.

2. In a rotary abrading device, the combination of: spaced end membersconnected by a central axial member, a plurality of spacers positionedat intervals around the central inember and extending axially betweenthe end members, inclined surfaces on the end members adapted to contactopposed ends of the spacers to move the spacers radially outwardly uponend- Wise movement of the end member, means to limit outward movement ofthe spacers including abutments provided on at least one of the endmembers, a plurality of `abrasive strips encircling the central memberand each having an end thereof extending outwardly between a spacer andan adjacent abutment, and clamping means cooperating with the centralmember adapted to move the end members axially toward each other,whereby each abrasive stripmay be clamped between a spacer and one ofthe abutments.

3. In a device of the class described, the combination of: a rotatablehousing having axially movable ends, a brush holder extending axially ofthe housing, brushes on the brush holder extending outwardly from thehousing, means on the housing forming an axially extending socket forreception of the brush holder, an abrasive strip extending outwardlythrough the socket adjacent the brushes, cam surfaces on the ends of thehousing adapted to contact opposed ends of the brush holder, and axiallymovable clamping means associated with said housing adapted 4 to movethe brush holder outwardly in its socket to clamp the abrasive stripagainst a wall of the socket.

4. In a device of the class described, the combination of: a rotatablehousing having axially movable ends, a plurality of spacers extendingaxially between the housing ends, means on the housing forming axiallyextending sockets for reception of the spacers, an abrasive stripassociated with each of said spacers extending outwardly through thesocket therefor, cam surfaces on the housing ends adapted to contactopposed ends of the spacers, and axially movable clamping meansassociated with said housing ends adapted to move the spacers radiallyoutwardly in their respective sockets to clamp each abrasive stripbetween a spacer and a wall of its socket.

5. In a device of the class described, the combination of: a rotatablehousing, a plurality of cylindrical brush holders extending axially ofthe housing, brushes on the brush holders extending outwardly from thehousing, means on the housing forming axially extending sockets forreception of the brush holders, an abrasive strip associated with eachof said brush holders and extending outwardly through the sockettherefor, cam surfaces on the housing adapted to contact opposed ends ofthe brush holders, and axially movable clamping means associated withsaid cam surfaces adapted to move the brush holders radially outwardlyin their respective sockets to clamp each abrasive strip between a brushholder and a wall of its socket.

6. In a device of the class described, the combination of: a rotatablehousing, a plurality of brush holders extending axially of the housing,brushes on the brush holders extending outwardly from the housing,axially extending fingers on the housing forming sockets for receptionof the brush holders, an abrasive strip associated with each of saidbrush holders and each extending outwardly through one of said sockets,cam surfaces on the housing adapted to contact opposed ends of the brushholders, and axially movable clamping means associated with said camsurfaces adapted to move the brush holders in their respective socketsto clamp each abrasive strip between a brush holder and a wall of itssocket.

7. In a device of the class described, the combination of: a rotatablehousing having axially movable ends, a plurality of cylindrical brushholders extending axially of the housing, brushes on the brush holdersextending outwardly from the housing, axially extending ngers on thehousing forming sockets for reception of the brush holders, an abrasivestrip associated with each of said brush holders and each extendingoutwardly through one of said sockets adjacent the brushes, cam surfaceson the ends of the housing adapted to contact opposed ends of the brushholders, and axially movable clamping means associated with said housingadapted to move the brush holders outwardly in their respective socketsto clamp each abrasive strip against a wall of its socket.

8. In a rotary abrading device, the combination of: a rotatable housing,said housing comprising two duplicate halves, means to maintain thehalves of the housing in operative relationship including a centralmember extending axially of said halves of the housing, a plurality ofbrush holders extending axially of the housing, means on the housinghalves forming axially extending sockets for reception of the brushholders, a plurality of abrasive strips encircling 5 6 the centralmember and each having an end REFERENCES CITED thereof extendingoutwardly through one of the d sockets, cam surfaces on the housinghalves lrghf fligwggeerences are of com in the adapted to contactopposed ends of the brush holders, and clamping means cooperating with`5 UNITED STATES PATENTS the central member adapted to move the housingNumber Name Date halves axially toward each other, whereby the 2,194,577Vonnegut Mar 26 1940 brush holders may be moved outwardly in their413,165 Bonkowski Dec' 24' 1946 respective sockets to clamp eachabrasive strip between a brush holder and a wall of its socket. 10

WILEY W. WICKMAN.

